Zoledronic acid side effects benefit for osteoporosis and side effects

Zoledronic acid is a pharmaceutical drug used to treat high levels of calcium in the blood that may be caused by certain types of cancer. Zoledronic acid goes by the brand names Zometa and Reclast, Zoledronic acid is in a class of medications called bisphosphonates. It works by slowing bone breakdown and decreasing the amount of calcium released from the bones into the blood.

Zoledronic acid side effects
Osteonecrosis has been associated with the use of bisphosphonates. Side effects of intravenous zoledronic acid could include heart rhythm abnormalities. In one study, serious atrial fibrillation — in which the upper chambers of the heart beat rapidly but weakly — affected significantly more patients in the zoledronate group compared with the placebo group.

Once a year Zoledronic acid treatment
Zoledronic acid is being tested for the treatment of osteoporosis, given once a year by intravenous method. A once-a-year infusion of zoledronate, can reduce the risk of fractures of the spine and hip in postmenopausal women with brittle bones due to osteoporosis.

Once-yearly zoledronic acid in the prevention of osteoporotic bone fractures in postmenopausal women.
Clin Interv Aging. 2008; Lambrinoudaki I, Vlachou S, Galapi F, Papadimitriou D, Papadias K. 2nd Department of Obstetrics and Gynecology, University of Athens, Aretaieion Hospital, Greece.
Zoledronic acid is a nitrogen-containing, third-generation bisphosphonate that has been approved for the treatment of postmenopausal osteoporosis as an annual intravenous infusion. Zoledronic acid is an antiresorptive agent which has a high affinity for mineralized bone and especially for sites of high bone turnover. Zoledronic acid is excreted by the kidney without further metabolism. Zoledronic acid administered as a 5 mg intravenous infusion annually increases bone mineral density in the lumbar spine and femoral neck by 6.7% and 5% respectively and reduces the incidence of new vertebral and hip fractures by 70% and 41% respectively in postmenopausal women with osteoporosis. Most common side effects are post-dose fever, flu-like symptoms, myalgia, arthralgia, and headache which usually occur in the first 3 days after infusion and are self-limited. Rare zoledronic acid side effects include renal dysfunction, hypocalcemia, atrial fibrillation, and osteonecrosis of the jaw.

Zalendronic acid study in NEJM
In this randomized, double-blind, placebo-controlled trial, 1065 patients were assigned to receive yearly intravenous zoledronic acid (at a dose of 5 mg), and 1062 patients were assigned to receive placebo. The infusions were first administered within 90 days after surgical repair of a hip fracture. All patients (mean age, 74 years) received supplemental vitamin D and calcium. The median follow-up was 2 years. The findings: An annual infusion of zoledronic acid within 90 days after repair of a low-trauma hip fracture was associated with a reduction in the rate of new clinical fractures and improved survival.
Comments: It would be helpful to know what the outcome would be in a 2, 3 or more year followup or whether this approach is better or safer than the use of calcium and vitamin D supplements, along with exercise.